The battles of Fort Sumter, Bull Run, Shiloh and Gettysburg were major conflicts of the American Civil War. In April 1861, the Battle of Fort Sumter started the war after Confederate soldiers surrounded the fort and ordered Major Robert Anderson to surrender. During a four-month stalemate, Anderson awaited Union provisions, while President Lincoln attempted to negotiate a peaceful solution. The Confederacy was unwilling to allow Union reinforcements, so General Pierre Gustave Beauregard ordered troops to attack.
In July 1861, Lincoln urged General Irwin McDowell to quickly end the war by defeating Confederate troops at Bull Run in Virginia, clearing a path to the Confederate capital of Richmond. Both forces were poorly prepared for a complex military strategy, but the Confederate troops eventually gained the advantage, leading to an infamous Union retreat that forced the northern government to take the war seriously.
In April 1862, Confederate General Albert Sidney Johnston initiated the Battle of Shiloh, or Pittsburgh Landing, to prevent Union soldiers from occupying Corinth, a railway hub. Early on, the Confederates drove back the 42,000 Union troops led by Ulysses S. Grant, but General Don Carlos Buell soon arrived with 20,000 additional troops to secure a Union victory. The battle claimed approximately 62,000 casualties, including General Johnston.
In July 1863, General Robert E. Lee planned an attack in northern territory to divert forces away from ravaged Confederate cities. Despite resistance from his supporting officers, Lee moved against the Union Army of the Potomac, which was newly commanded by General George G. Meade. Motivated by recent victories in Chancellorsville, Lee ordered several overconfident attacks at Gettysburg, leading to defeat and 28,000 Confederate casualties.